The Long Tail of Long COVID-19: Broad and Extensive Increase in Utilization Within an Integrated Healthcare System.

Publication date: Apr 01, 2026

The impact of the emergence of Long COVID on healthcare utilization in a U. S. community setting remains underexplored. To examine the healthcare utilization of Long COVID patients compared with pre-COVID-19 era controls before and after SARS-CoV-2 infection within a large integrated delivery system. This was a retrospective cohort study of adult patients with documented SARS-CoV-2 infection (1/1/2021-6/30/2022) in a multi-site Northern California health system. Long COVID diagnosis was defined by at least one encounter with an associated International Classification of Diseases, Tenth Revision code and/or referral to Long COVID specialty care. Utilization outcomes included inpatient/outpatient encounters, laboratory/imaging/functional testing, specialty care referrals/encounters, and medication use. We used propensity-weighted difference-in-differences models adjusted for study month to compare outcomes between baseline and post-SARS-CoV-2 infection (Long COVID window). Results: Among 600,295 patients with 635,230 SARS-CoV-2 episodes, 3,545 met criteria for Long COVID care-seeking. Long COVID patients had higher baseline utilization and greater increases in post-diagnosis utilization in adjusted analyses. After propensity weighting, these differences persisted and were consistent across the study period, particularly in cardiac and pulmonary care. Total encounters per year were 29. 9 post and 14. 1 pre (Long COVID) versus 17. 7 post and 12. 5 pre (NO Long COVID). Total annual ED visits per 100 patients were 65. 1 post and 38. 0 pre (Long COVID) versus 38. 0 post and 32. 0 pre (NO Long COVID). Annual hospitalizations per 100 patients were 10. 5 post and 5. 3 pre (Long COVID) versus 7. 4 post and 5. 5 pre (NO Long COVID). Long COVID patients had higher healthcare utilization before and after diagnosis, with sharper increases across nearly all outcomes.

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